Through the trees and over the valleys the mourners came in a display of national unity that expressedIsrael'srevulsion at the murders of three teenagers.

Thousands of Israelis – young and old, many of them religiously devout – defied 90 degree temperatures to pay their last respects on Tuesday to Gilad Shaer, Naftali Fraenkel, both 16, and Eyal Yifrah, 19, whose deaths have sent shock waves through the Jewish state.

The teenagers' remains were discovered on Monday, 18 days after they were last seen on June 12 trying to hitch a lift from outside the Gush Etzion settlement in the West Bank.

The trio were shot after being abducted – according to Israeli authorities – by two known members of Hamas, the Palestinian militant group.

A day after their bodies were found hidden under rocks in an isolated field near Hebron, the youths were buried at the vast Modi'in cemetery in central Israel in a mass public event whose tone and dimensions resembled a state funeral.

They were brought to the cemetery in ambulances, their coffins wrapped in Israeli flags, after leaving their three home communities in separate processions.

Much of Israel's political leadership was present, including Benjamin Netanyahu, the prime minister, and Shimon Peres, the country's president.

Mr Netanyahu, who has blamed Hamas for the murders and pledged to make it pay, described the event as "a day of spontaneous national mourning" and said he personally identified with the bereaved families' grief.

"I know the pain of mourning. There is nothing worse than that," he told mourners, many of whom were in tears.

"But I also know that life has its own power, like a river which sweeps us forward and gives us the strength for renewal and hope."

So vast was the crowd of mourners – some of whom had come from far in fleets of buses – that the funeral was delayed for an hour and a half, forcing Mr Netanyahu to postpone his arrival and prepared remarks.

While few knew the teenagers personally, many professed intense feelings of kinship.

"I feel they were my children and I'm here to show respect and solidarity," said Matanya Handler, 38, an engineer from Modi'in, who said the event showed Israel was moving in a "different direction" from other countries in the Middle East. "They are educating their children to be martyrs, we educating ours to build and learn," he said.

"Even though I didn't know them personally, I still feel a connection to them and their families," said Shira, 22, a student from Givat Shmuel in central Israel. "The beauty of Israel is that it is all one family – if something happens to one person, it happens to everyone."

Yet the sense of unity was tempered by public agonising over the handling of a phone call one of the youths made to a police hot-line after his abduction in which he tells the operator: "They kidnapped me." Shortly afterwards, gunshots are heard on the tape, Haaretz reported after a gag order on the exchange was lifted on Tuesday.

Police subsequently failed to report the call to security forces, giving the murderers several vital hours to escape.

The murders have prompted a fierce political debate about how Israel should respond, with Right-wing ministers such as Naftali Bennett calling for extensive military action against Hamas.

His views have been countered by a more cautious approach from Mr Netanyahu and Moshe Ya'alon, the defence minister, who have indicated that they oppose escalating the conflict with Hamas despite authorising limited strikes in recent days against militant targets in Gaza, the coastal territory which the group controls. The strikes have been prompted by a recent wave of rocket salvos fired from Gaza into Israel.

The Israeli security cabinet was meeting for a second successive night on Tuesday to discuss a possible response, with one proposal being to deport Hamas members arrested in the West Bank in recent weeks to Gaza.

Mr Netanyahu and Mr Ya'alon have also suggested embarking on a renewed settlement building programme as a response – with one settlement supposedly to be built in memory of the three teenagers.

One Israeli official told the Telegraph that Israeli action would be tailored to address recent events rather than breaking the long-term deadlock with Hamas, which refuses to recognise the Jewish state.

"Israel has to maintain credible deterrence. It is critical that groups believe when they take acts such as this they will pay a price and bear responsibility for their actions," the official said.